Danish Headache Center has positive results with a chip implant on the jawbone and a remote device to activate the chip:
http://www.glostruphospital.dk/menu/Afdelinger/Dansk_Hovedpinecenter/Forskning/Klinisk+fors%C3%B8g+med+henblik+p%C3%A5+akut+behandling+af+klyngehovedpine.htm
http://www.dr.dk/sundhed/Sygdom/Hovedpine/Artikler/2011/0525100944.htm
It's in danish, sorry. The first link refers to the experiment, and the next link is a woman who has the chip. The top line says: "Surgery saved me from suicide headache". I am going to talk with one of the neurologists later this month...Â